Phase Change and Morphology in the Oxidation of Zinc Sulfide Powder

摘要

Fine zinc concentrates tend to become sticky when roasted in a fluidized-bed reactor. The oxidation of high-purity ZnS powders and ZnS concentrates with different particle sizes were studied in terms of phase changes and particle morphologies. The sample materials were directly oxidized to ZnO in a roasting process performed over 700℃. Zinc oxide particles with diameters less than 0.5 μm formed at 700℃; the particle size increased by grain growth at 900℃. The coarse ZnS concentrate formed the oxysulfate ZnO·2ZnSO_4 when roasted at 700℃; the sulfate transformed to ZnO at higher temperature.